Fellow introducing duck to plant (8)
I believe the answer is:
mandrake
'plant' is the definition.
(mandrake is a kind of plant)
'fellow introducing duck' is the wordplay.
'fellow' becomes 'man' (I've seen this before).
'introducing' is a charade indicator (letters next to each other).
'duck' becomes 'drake' (drake is a kind of duck**).
'man'+'drake'='MANDRAKE'
'to' is the link.
(Other definitions for mandrake that I've seen before include "Poisonous plant with large forked root" , "Plant once believed to shriek when pulled up" , "Plant with forked root used in magic" , "Exotic plant" , "Eurasian plant with purplish flowers" .)